


Kit In The Cockpit

by KissKinesthesia



Series: Kit In The Cockpit Universe [1]
Category: Voltron: Legendary Defender
Genre: AU where Littles are a known thing in human culture, Accidents, Age Play, Age Regression/De-Aging, Baby Keith (Voltron), Bed-Wetting, Comfort, Crying, Daddy Kink, Diapers, Embarrassed Keith (Voltron), Explicit Sexual Content, Fluff, Gen, Guardian Hunk, Guardian Lance, Guardian Shiro, Humiliation, Juvenile Keith, M/M, Non-Sexual Age Play, Non-Traditional Alpha/Beta/Omega Dynamics, Omorashi, Only instead of ABO its different, Praise and affection, Public Humiliation, Team Bonding, Team Fluff, Team as Family, Tickle Fights, Voyager Pidge, Wetting, Will also eventually include sexual enjoyment of ageplay/diapers, babying, caregiver shiro, cg!shiro, ddlb, diaper use, little!Keith, messing, much fluff, or 1001 times keith shat himself and 5 times he didnt, so soft, this isnt a furry fic dont take the title too literally
Language: English
Status: In-Progress
Published: 2019-12-10
Updated: 2020-12-26
Packaged: 2021-02-26 01:22:25
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 17,068
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21745213
Author URL: https://archiveofourown.org/users/KissKinesthesia/pseuds/KissKinesthesia
Summary: Being a Juvenile isn't easy when you're caught in the middle of an interstellar war. Thankfully, Keith has Shiro as his caretaker.In which Keith gets caught wetting his bed and Shiro puts him in diapers as consequence. - But how long can Keith keep his babyish tendencies a secret from the rest of the team?A multi-chap ageplay fic featuring lots of fluff and team bonding as Keith settles into his role.
Relationships: Hunk & Keith (Voltron), Keith & Lance (Voltron), Keith & Shiro (Voltron), Keith/Shiro (Voltron)
Series: Kit In The Cockpit Universe [1]
Series URL: https://archiveofourown.org/series/2082573
Comments: 68
Kudos: 312





	1. Don't Start Now

Some say the Juveniles were gifts from Heaven; sent to heal and restore balance to one’s heart and home. Other tales claim they are separate creatures, born from rare and precious fissile elements; Worth fortunes, yet needing so much attention and care. No matter who told the tales or where they came from, they all came to describe the same thing- An eternal child that healed and impassioned those around them. 

Keith personally didn’t see much value in the role. He would’ve much rather been born a Guardian, or a Voyager, as they were more common and stable on their own. As it was, Keith was struggling to keep up the appearance as anything but-  Over time, all roles eventually succumbed to their needs, and Keith was no exception-- Which was bad news, when you were supposed to be a space hero fighting an intergalactic war. 

  
  


Every role had it’s duties to the world, but so too did it have it’s needs. The Guardians managed, maintained, guarded and cared for the people, land and property. They easily made up more than half of the population, and sought out families. 

  
  


The Voyagers were slightly more rare, making up a large chunk of the populous. Voyagers made their stakes in the lost and yet-found. They were the explorers, tinkerers, architects, scientists and detectives of the world. Seeking out the new that had yet to be known. 

  
  


And then there were the Juveniles-- Rarest of all, and few and far between. They ran the line from artists and celebrities, to therapists and prized goods, depending on where you lived. They varied a lot as independent specialists in their fields, and often lit a fire in the hearts of others. Making excellent leaders and inspiring people. But their talent came with a heavy drawback. And that drawback was currently making it’s needy little head known in the most embarrassing way.    
  


  
Keith swore he was starting to lose his bladder control. 

  
  


Fantasies of soft clothes, toys and diapers had always followed him as he’d grown, but that didn’t mean he  _ needed _ them-- or that was the lie he’d told himself, at least. Now, as he woke up in soaked sheets and wet pajama pants for the upteenth time this morning, he was starting to worry he needed help- Help that he wasn’t exactly going to receive as one of five humans _ in space.  _

  
  


Some Juveniles were lucky, and went in and out of babyhood through their headspaces. Able to live functionally as an adult their entire lives, and regress and de-stress needed. Others were doomed to a life of bottles and diapers from birth, perfectly happy to live that way for the rest of their lives.

  
  


Keith had always hoped his ability to make it through the Garrison on nothing but supplements and will-power would be enough to last him his entire life-- Only on rare occasions did he regress and miss class, lucky enough to have Shiro around to care for him when needed.-- But it seemed that wasn’t the case. 

  
  


He had known the warnings about what would happen from overuse of medications to repress his baby tendencies, needs and behaviors-- his littler headspace-- But somehow he never thought he would actually suffer the repercussions, until today. 

  
  


He grimaced at the smell, the uncomfortable wetness. This would be one of many times he had wet the bed, and worse yet, he had even begun having accidents in the daytime as well. They were much less common, but they had started to become more frequent with his night time wettings, and Keith was starting to worry. 

Even if he had wanted the life of a full time Juvenile baby, he knew he couldn’t afford it while leading Voltron. Nevermind ask anyone for help. What kind of leader wets their pants and needs diapers? Keith flushed with shame just thinking about it. 

There was just no way. 

So Keith got up from his bed and did what he did every timer this happened-- Stripped off his sheets, wet pants, put them into his laundry hamper, cleaned himself off, and padded down to their communal laundry room while it was still early in their sleep cycles, and no one would see him. 

  
  


It was quiet and dark. Nothing but the soft blue neon lights illuminating the hallways and the muted hum of the castleship greeted him as he traversed the dark corridors. Finally he came upon a lone, lit room in the middle of their dormitories. Doorless and always brightly lighted. Keith squinted in the brightness as he brought in his small hamper of soiled garments, setting them on the ground next to him as he fiddled with a laundry machine. 

  
  


The room was all too reminiscent of Earths Laundromats. Only cleaner, less crowded, and free. The little disused altean-coin slots on the machines never failed to catch his eye every time he came here. It would be one of the only thoughts to distract him from his internal anxieties as he grabbed one of the small boxes of space-detergent off the shelves and gingerly poured it into the machines designated area. Lifting up his laundry hamper towards the open washer and-  “Keith?”

-fucking dropping it on the ground and jumping ten feet in the air. Keith didn’t scream, but it was more than obvious by his posture and his jolt that he really hadn’t been expecting anyone to see him there. Not even Shiro. 

  
  
“Oh, I’m sorry!” Shiro chuckled lightheartedly, as he came up behind Keith to place two big calming hands on his shoulders. “I didn’t mean to scare you.” He soothed, hands rubbing up his shoulders sweetly. Voice honeyed in every syllable that had Keith easing despite himself. A short exhale escaping him as he finally began to breathe again. 

  
  


“What are you doing up so late?” Asked the guardian, much to Keith’s anxiety. “You should be asleep. We have a big day tomorrow, you know.”

  
  


“Just… doing some laundry.” Keith said, hoping Shiro wouldn't notice what he was doing. “What are you doing up?”

  
  


“Couldn’t sleep. Thought I’d go for a walk.” Shiros eyes turned on his hamper. “Are those bedsheets?

  
  
  


“No?” He had always been a bad liar, and he knew the more time Shiro had, the sooner he would figure it out. Rushing to pick up his dropped hamper, Keith tilted it towards the basin to dump it all out-- But Shiro caught him by the wrist before he could. 

  
  


“Wait.” Shiro spoke. The more serious, albeit gentle tone of his voice had Keith freezing in place like it were a command. The younger man gulped and his heart sank as Shiro reached into the hamper and pulled out a dark blue bed sheet, catching him in his lie.

  
  


“These  _ are _ bedsheets. Why are you washing them?” Shiro raised a brow towards him skeptically. 

  
  


Keith knew he was already caught, but was too desperate not to try anyway. “They just needed a change, that’s all.” He reached out a hand to try and tug his sheet back, but Shiro wouldn’t let go of it. Only managing to jostle the older mans large fist by a mere decimeter. His figure, his silence and stature tall and foreboding. 

  
  


Internally, Keith begged for the earth to swallow him whole. “Shiro-” But it was too late.

  
  


Bringing the offending garment to his nose, Shiro took a sniff- Eyes widening, nostrils flaring, Shiro returned his gaze to him, fully recognizing the smell. “Keith. Did you have an accident?” 

  
  
  


Keith felt his stomach sink into the floor.  Not even trying to hide the way his expression twisted into embarrassment and shame,hands coming over to hide his face with a groan. 

  
  


“Oh, Keith.” Shiro crooned, feature softening at the sight, as he put back the sheet in favor of stepping into Keith’s space and pulling him into a hug. “It’s okay, it's okay. Was it a nightmare?” 

  
  


“No.” Even to his own ears, he sounded like a baby. Reluctantly, he let himself be held as Shiro’s arms stroked up and down his back. 

  
  


Shiro had been the closest thing to a caregiver Keith had ever had. Spotting his talent and saving him from a life of Juvenile Delinquency, where he would be forever in the system or auctioned off to a forever home, he had been Keith’s only confident, as well as the only person in the castle who knew about his role. 

  
  


Shiro was also his Daddy. 

  
  


As of last month, they had finally gotten together. By all means they should’ve been a perfect mated pair by now, but Keith had always been reluctant to let Shiro baby him, and Shiro had always been respectful of Keith’s wishes not to-- But they had their moments anyways. Sometimes Keith slipped. Sometimes Shiro did too. 

It happened. 

He just didn’t want Shiro to feel like he _had to be_ his caretaker. For a Guardian there could be no greater joy, healing or fulfillment in life, but Keith always worried, always felt like he forced it on others to tend to him by default. He didn’t want that for Shiro, despite his many affirmations that he didn’t mind.    
  
  


It seemed like now was about to be one of those times. So much for being alone. 

  
  


Heavy, gentle hands soon smoothed up into Keiths hair, and he resisted the urge to cry. Keith had no idea where the emotions were coming from, but it wasn’t uncommon for them to suddenly overtake him like this. Spontaneous and unexpected. He felt his eyes welling up with the weeks anxieties as his hands climbed up around Shiro’s back, returning the hug. 

  
  


Shiro must’ve sensed it, because his voice dropped a level softer and his arms held him tighter. “Oh, sweetie.” He soothed, and gave Keith a soft squeeze that had the tears finally spilling over his lids. “It’s okay. It’s just an accident. It’s normal for juveniles.” 

  
  


The way Keith swallowed and gripped Shiro’s night shirt must’ve been indicative, because Shiro seemed to take notice of his silence.    
  
  
“Baby?” Shiro prompted. Sensing something else.    
  
  
Reluctantly, Keith pulled back a little from the hug, and Shiro gave him room to look up and meet his eyes. “It’s not-” He sniffed, wiping his nose with the back of his wrist. “It’s not _a_ accident Shiro.”

  
  


“ _A_?” Shiro echoed, brow furrowing. “A….*Oh*.” Brows lifting in realization, Keith had seen enough, and ducked back into the comfort Shiro’s warm chest provided. The older Guardians arms locking back around him automatically. 

  
  


“This isn’t the first time, is it?” Shiro asked, and Keith nodded pathetically into his chest. His tears were already drying, but the shame was heavy enough to keep him there anyways.    
  
  


“Sweetheart, why didn’t you tell me?” Shiro asked again. A minute passed in silence, and when Shiro got no response, he let out a little sigh before pulling Keith up into his arms and setting him down on the bench. “Just sit tight okay baby?”   
  
  
“Okie.” Keith sniffled more than spoke as he watched Shiro dump his soiled laundry into the machine. Closing the top-lid and turning it on before returning to Keith. Sitting down next to him on the bench before pulling him into his lap and holding him close. Any other time Keith would have shrieked and squirmed away, but it was late enough that he was confident no one else would see. 

  
  


That they were a couple was one thing, but Keith didn’t want to give the rest of the team any reason to suspect he might not be a Voyager as he’d led them to believe. 

  
  


“How long has this been going on?” Shiro spoke, gently shifting Keith in his arms to lay him on his shoulder.    
  
  
“A month..” Keith answered quietly, calming as Shiro stroked his back. He really hadn’t wanted Shiro to find out about this, and it showed. 

  
  
  


“A month?” The slight alarm in his Daddy’s voice made Keith frown. “That’s an awfully long time to be hiding all this. Why didn’t you tell me?” Shiros voice was so soft and gentle, Keith couldn’t help the heavy, guilty feeling in his heart. 

  
  


Suddenly his instincts flared, and everything came rushing out. “Because I know you’ll say that I need diapers and that I’m a Juvenile and that I’m too little to be big anymore and,- And-” Keith sniffed, wiping his face as more tears leaked out. “I don’t want to stop being big! I can’t- I can't leave Voltron- I have to--”

  
  


“Keith, Keith, sweetheart, Shh, Shh,” Shiro rocked him held him close, “It’s okay, it’s okay. Baby you know I won’t ever make you be anything you don’t want to be, right?”

  
  


Keith sniffled, blinking big wet eyes at him. “You won’t?”

  
  


“Of course not.” Shiro kissed his forehead, and each of his wet red cheeks. “That might’ve been the standard on Earth, but it doesn’t have to be here.”

  
  


“You’re not,” Sniff. “You’re not… Disgusted?” 

  
  


“Aww, Keith,” Shiro crooned, giving him a big squeeze and rocking him back and forth. “You’re so cute. I would love to baby you.” he said, wiggling a finger in Keiths face with a tease, which of course made Keith internally combust and hide his face.    
  
  


“Shirooooo!!”

  
  


“And I _could_ baby you, if you’d let me.” Shiro chuckled and leaned down to smooch his forehead. “Though it might be worth looking into some pullups for you.”   
  


  
“Shiro!” Keith shot up, uncovering his face to shoot his Daddy a glare.

  
  


“I don’t want to force you into it but I don’t think you should resist it completely either. It’s not healthy to avoid it so much, baby boy. You’ve been neglecting your little side for years. Maybe you should give it a try?” 

  
  


That was a much more reasonable suggestion, as much as Keith hated to admit it. “I know.. I just…”

  
  


“Just what?” Shiro pecked him on the cheek, and got a bashful little smile out of him for his efforts. 

  
  


“I don’t know, I guess.. I’m scared you’ll think of me differently. Or… it’ll make me a baby forever. You know how hard it is to stop once you’re started.” Well,  _ Shiro _ didn’t know, but Keith did. Once you began, it was very easy to become diaper-dependent. It could easily mean re-doing potty training all over again if they weren’t careful, as most littles ended up that way as they got older.

  
  


“I know.” Shiro soothed, cupping his cheek. “But the important thing is that you’re safe and healthy first and foremost. You don’t have to be a baby all the time to use diapers.” It was hard to stay mad or upset when Shiro was looking at him so lovingly. Reminding him too much how Shiro adored him. 

  
  


“Maybe if you just let yourself be all cute and little once in a while, you’d even have less accidents.” Shiro teased, and started tickling his tummy, making Keith giggle. A high childish sound that was much too adorable to be real. “Would it really be so bad?” Shiro asked, a manic grin on his face. “You like it when I hold you. And kiss you. And bounce you.” He said, leaning in and planting a bunch of messy kisses onto Keiths cheeks as he wriggled and flailed in Shiro’s lap. 

  
  
  


“You like it when I call you baby,”  _ Smooch smooch smooch _ , “You like it when I rock you to sleep!”

  
  


“That!” Keith gasped between rounds of laughter, “That! That Doesn’t- Ahaha, that doesn’t mean anythihehehang!”   
  


  
“Are you suuuuure?”    


  
  
“Ahaha, aha yes! Yes! I’m su-AAHHHahaha!!”   


  
  
Keith didn’t have much time to prepare, because Shiro finished him off by lifting up his shirt and blowing a big wet raspberry right onto his tummy. Making Keith all but scream with high pitched little laughs and giggles.    
  


  
“Daddy! Daddy please, sto-AHAHAHA!” Shiro blew another, and then another, until he was finally satisfied enough to lean back and hold his baby sweetly against him, chuckling as Keith calmed down.    
  
  


“I hate you.” The words held absolutely no venom between Keith gasping to breathe and ebbing cute little baby giggles, And Shiro knew as much. 

  
  


“I love you too.” Replied Shiro, smooching him once more. “And I’m getting you some pullups.” 

  
  


“Ugghhh.” 

  
  


“I’m your Guardian. Do you really expect me to just let my Baby struggle to sleep and wash his sheets every night?”

  
  


Keith mumbled and pouted, but sighed. “No.” Shiro was right. He was only looking out for him. It just kinda sucked a lot, was all.    


  
  
“And I’m going to make sure you’re wearing them too.”

“UGH.”   
  
  
“I know, I know.” Shiro smooched him again. “Every night before bed. If you do good you don’t have to wear them anymore. Deal?”

  
  


“You say that like I have a choice.”

  
  


“Would you like to wear diapers instead?” Keith glared up at him, and Shiro only smiled back down at him like a smartass.

  
  


Groaning, Keith crossed his arms but relented. “Deal.”   


  
  
“And I’m helping you change your sheets tonight.”  _ Smooch _ . “We can cuddle up after.”

  
  


Keith made a loud whiney noise in retaliation, but he knew at this point that there was no arguing. Shiro was in full caretaker mode now, and he always got what he wanted. Not that Keith ever really minded- He trusted Shiro enough to know he had Keith’s best interest at heart. All decisions he ever imposed on him only ever worked out for a reason. That he enjoyed it was a testament to how much he loved him, loved taking care of him, and how great a guardian he was. 

  
  


So Keith sighed and contented himself to cuddling up with Shiro for the night as they watched the Laundry machines spin through their wash cycle.

  
  


* * *

  
  
  
  


After Keith’s sheets and pants had been cleaned and dried, the two walked back to his room in comfortable silence. He was grateful that Shiro let him carry his own Laundry hamper back, and hoped Shiro would be satisfied with his cuddles and scolding to let him off for tonight. Not yet willing to admit he enjoyed Shiros tickles and hugs more than he said- though Shiro seemed to know already.

The doors slid open softly, and Keith set down his hamper on the soft carpet. “Thanks for… well. Everything tonight.” He smiled. “I can take the rest from here.”

  
  


“Sorry.” Shiro leaned down to press a warm kiss to Keiths’ forehead. “You’re not getting out of this that easily.”

  
  


Keiths' expression fell flat immediately.“Dammit.” He cursed, crossing his arms and pouting.

  
  


The older guardian chuckled at the display, before gently taking Keiths hand and leading out of the doorway. “C’mon. We’ve got one more stop to make before I make your bed.”

  
  


“Before  _ we _ make my bed.” Keith corrected, but followed him nonetheless. Not bothering to ask where they were going, since he knew he wasn’t getting out of it anyway.

  
  


Eventually Shiro led them into a small utility room. It was behind the door of their utility closet, but when they stepped inside it looked more like a small study than anything else. Lined with high ceilings and circular walls, it seemed to contain an endless bookshelf staffed with everything from cleaning supplies to cooking utensils, to the very laundry detergent they had used earlier. Every section was labelled neatly like a library. But for Things instead of books. They all had access to it, but Keith had only been here a number of times before- Not nearly as familiar with it as Hunk, or Coran.

  
  


Shiro continued into the room, so Keith quietly followed him to the back of it. Stopping before what appeared to be a very large vending machine-- If vending machines had smart-computers and holo-selection screens and were built into the wall. 

  
  


“Whats this?” Keith asked curiously.

  
  


“The alchemiter.” Shiro answered, and began looking through the selection on the holo-screen. “For everything we don’t already have, this machine can make it for us.”

  
  


“Oh.” A moment passed, before Keiths brows rose in realization, turning to Shiro once more. “Is this where we got our extra pairs of clothes?”

  
  


Shiro met him with a smile that turned his insides to mush. “My smart little boy.” 

  
  


As much as Keith would’ve liked to, there was no hiding the smile those words elicited from him. But before he could make any mock-complaints about it, he heard the sound of the Alchimiter whirring to life. Panels lighting up in bright neon blue and-- “Wait a minute.” Keith’s brows rose once more, as he finally put the pieces together. A blush tinging his cheeks. “Do we have to do this tonight?” Keith sent Shiro something of a desperate look.

  
  


Shiro of course, only smiled at him more and kissed his forehead. “Yes.” 

  
  


The alchimiter beeped, making another rustling sound before a loud  _ thump  _ echoed from inside of it. The little horizontal doorway swinging to and fro’ at the bottom. Shiro reached inside and pulled out a large plastic package of what was unquestionably diapers. Or in Keith’s case, pullups. Shiro held it up to Keith to observe, and Keiths blush worsened. It was covered in bright colors and shapes, cartoon characters, as well as various writings in Altean. The see-through container allowed them to see the rows of diapers neatly stacked from the top.    
  
  


Shiro held Keiths hand all the way back to his room. He asked Keith if he wanted help putting them on, but Keith declined to put them on in his bathroom by himself, only to reappear a couple minutes later wearing a soft, pink pull up with little red hearts and stars on it. It was...comfy, and soft, and no matter how much he wanted to, Keith couldn't hate it. 

  
  


But he might be able to hate the absolute look of fucking glee and adoration that covered Shiro’s face as soon as he stepped out of the bathroom. He was even _ covering his mouth _ , god, and it only made Keiths mortification worse. 

  
  


“Shut up.” Keith struggled to frown, trying not to let Shiro’s smile infect him. 

  
  


“I didn’t say anything.” Shiro moved closer to him, opening his arms, needing to hold him.    
  
  


“You thought it.” Keith accused.

  
  


“Thought what?”

  
  


“You know.” Keith smothered his face into Shiro’s chest and whined.

  
  


“You’re adorable.” Shiro chuckled, hugging him briefly before unceremoniously picking him up and making his baby squeak. Keith automatically clinging to him as Shiro settled on him on his hip and smooched his cheek. Carrying him the short distance from his bathroom to his freshly made bed. 

  
  


“I thought we were gonna make it.” Keith whine, weathering the most adorable glare at him.

  
  


“You were taking too long.” _Smooch._ “You’re lucky I didn’t walk in and help you into your pullup too.” Shiro leaned forward, grabbing Keith in such a way that allowed him to lay him down into the bed, before he himself began to settle into it with him.    
  
  


“Stop being so smug.” Keith said, sticking a finger into Shiro’s chest as if it would do anything. 

“No.” Shiro said like a sassy asshole, before wrapping his arms around Keith and squishing him to his chest, causing Keith to giggle and squirm as he settled in comfortably. 

“How do they feel?” Shiro asked.

  
  


Keith sighed into his chest, feeling his blush burning his cheeks. “They feel.. Soft.. and firm. And… “   
  


  
“Nice?” Shiro supplied, lips grazing his forehead warmly. 

  
  


“Yeah.” Keith sighed, finally giving in and cuddling into his Daddy.

  
  


“See? Not so bad is it?”

  
  


“No..” Keith mumbled. “I guess not…” Shifting slightly, Keith rested his chin on Shiro’s rib cage and peered up at him through the soft blankets, catching his attention. “I love you Shiwo.” Keith said. Letting his speech soften and his voice highten-- Feeling his little space beginning to sink into him. A familiar, albeit old sensation he hadn’t allowed in quite a while. Not since Shiro left the Garrison, he was sure. 

  
  


Shiro must’ve recognized it, because his smile was so adoring and bright, Keith almost thought he was crying. The older man gently lifted up his hand to stroke through Keith’s soft long hair, not hesitating to cover his face in sweet kisses. 

  
  


“I love you too, baby boy.” Shiro brought him up into another hug, giving him an affectionate squish that nearly made Keith well up again. He loved Shiro so much. 

  
  


“Now, it’s time to close your eyes and drift off to sleep. Do you think you can do that for Daddy, sweetheart?” 

  
  


Keith nodded up at him, the movement already slow and distracted with sleep. “Mhm,” He hummed. “I can do that Dada.”

  
  


“Good boy.” _Smooch_. “Goodnight baby.”

  
  


Little Keith yawned a bit, snuggling into Shiro yet again as his eyes finally closed and his hands settled up near his cheeks in tiny fists. “Nini Daddy.”

  
  


It took not much longer than a minute before Keith fell right asleep in Shiro’s arms. The guardian watching with adoration as his baby slipped his thumb into his mouth, cradling him close and protectively, only to fall asleep with him not long after. 

  
  
  


**Notes for the Chapter:**

> Thank you all so much for reading! If you liked it, please leave a comment letting me know! more comments = faster updates, for I am fickle and easily motivated. 
> 
> Leave any ideas or suggestions down below and I might put it in the fic, or write something with it later on. <3 
> 
> come harrass me on twitter @kisskinesthesia


	2. A Lamb in Wolfs Clothing.

**Summary for the Chapter:**

> Keith slips up in the best way.

**Notes for the Chapter:**

> Thank you so much to everyone who commented last chapter! Your comments really motivated me to keep this story going, more than anything, so this chapter goes out to you.
> 
> Note: This chapter will include wetting and messing. You have been warned.

The day is as stressful as Shiro had warned him about, and as exhausting as Keith had expected. 

Freeing a Galra occupied planet was not unlike stomping out a forest fire whilst covered in gasoline. It’s a miniature war on strange land. All the work is rarely done in one setting. 

One day bleeds into the next, and the next, and the next. After they’re done fighting for the lives of the innocent, there’s yet more work to do cleaning up the mess they’ve left in the process. Rebuilding the broken infrastructure, providing food and resources, and helping the people who live there make a plan for their futures. 

It’s a lot of cleaning, securing, makeshift soup-kitchens, construction and manual labor finished off with planning, delegating, and calling around what precious resources they’ve already made. By the time the newly-freed denizens are stable enough to continue on their own, they’re all bone-deep with exhaustion. Every muscle aching and sore after they’ve allowed themselves to sit long enough to feel it-- and by then, there’s usually another planet sending out a distress signal from across the galaxy. Beckoning them for yet another rescue. 

But that planet hasn’t called yet. And the Galra are nowhere near. 

The armor hits the carpeted floor of his room like a shell. Suit peeling off his skin with a layer of dirt and mud. In the shower he spends a little too long zoning out over the pristine white porcelain, while the heavy experiences of the week sink into the past behind his eyes. When his back finally hits the bed, he knocks out at the first blink.

Keith doesn’t dream, but he wakes up earlier than he knows he ought to. 

From the moment he opens his eyes to the ceiling of his bunker, he feels it. Instinct working in the back of his mind. Producing a tempting, but familiar sensation Keith hesitates to name. If he names it, he has to acknowledge it. And if he acknowledges it, he might do it. _No, not now. Not yet._

It’s the stress of the past four days seeping out of him like dense fog over calm ocean. Petering out and evaporating like a ghost over a wide, narrow space, only for a new, warmer, softer sensation to creep in behind it. 

He forces himself to sit up and stand, ignoring all the soreness in his limbs. Pacing and walking about his room, from door to wall and back again. The more he moves, the more he can forget his feelings-- But as he opens his door and pads out quietly out into the dimly lit hall, he realizes something. 

He’s alone. No one else has woken up yet. 

All his senses stretch out in the realization, searching for a single sound in the night. It’s so quiet, Keith can hear his own breath. The gentlest, smallest of smiles taking his features in the darkness, giddy and gleeful.

There’s a strange excitement that comes with the realization that he’s alone in a usually occupied space. Always has been. Like a child excavating out a hiding spot somewhere they know they shouldn’t be. 

He turns on the lights to their communal kitchen, meanders through their fridge and pantry for a bowl and some cereal when his brain betrays him and the thoughts become inescapable. Pattern recognition is his enemy today, and the childish feelings, the space-themed cereal in his bowl-- The pull-up he didn’t realize he was still wearing until now because he was _too comfortable_ too sleepy to notice it earlier-- He can’t ignore any of it anymore. 

After a moment, Keith sucks in a breath and presses his hand down to check it, finding it surprisingly dry. And then it hits him. 

Like a warm blanket fresh from the dryer, it encompasses him. Settling down from above, an inescapable hydraulic press of his own feelings. A silent pull from his own mind to enter a space that lies beyond all his walls. A space where his mind lingers between his very reality, and his thoughts become simple and small. 

He can’t help but recall what Shiro had said, the night before that mission. How he wets some nights, and not on others, but always when he's too relaxed or too stressed-- always on the cusp of one extreme or another. A pattern too obvious to ignore. 

Suddenly far too self conscious, Keith hurries back to his room with his cereal and locks the panel doors behind him. He sets down his bowl on the carpet, checks the time, and thumbs at the edge of his pajama pants as if he were standing on the edge of a cliff. 

_“You’ve been neglecting your little side for years. Maybe you should give it a try?”_

* * *

  
  
  


If Keith were honest with himself, he didn't hate it. Not the diapers, not the headspace, the incontinence, or even the idea of being babied by others. He didn’t even hate that he liked it. 

But enjoyment of juvenile tendencies was tied to his feelings. And feelings-- Feelings were embarrassing, awkward, and extremely personal. A private, sacred thing Keith had always held close to his chest. Always too scared of showing them, lest he get hurt. A complex inner conflict Keith had no desire to solve anytime soon, nevermind explain. 

He had always had a hard time expressing his feelings in public; forever afraid of the judgement of others, what they would think of him and how they would feel. Lance already mocked him for just about everything, and Hunk naturally would always back him up by virtue of their relationship. Pidge was a neutral party, neither helping nor abating-- And Allura and Coran would no doubt be confused at the least, and disturbed at the worst. Just the thought of making them feel that way- Being a walking eyesore in front of them all like that, made his stomach churn and his heart sink painfully into his sternum.

When he turned eighteen at the Galaxy Garrison, and all the guys in his sector were showing off their signs, Keith lied and reported to his instructors that he was a Voyager instead of a Juvenile. As far as he knew, Lance, Hunk and Pidge still believed that to be the case, and that was just the way Keith wanted it. He didn’t plan on changing that anytime soon. 

He would hide it until the very end, until it interfered with missions, or he died trying.

It’s been so long. Even the thought of doing this brings him back to Shiro, who’s presence is deeply intertwined into all his most recent Indulgences. When was the last time he did this on his own? 

Keith slides off his pajama pants and feels the soft carpet underneath his toes. The slightly rough, worn texture of it under his palms as he crouches down on hands and knees. He thinks he might actually have been a real baby the last time he chose to act like one. 

It takes a while to get comfortable. Even alone, he’s still shy about letting himself go. Always looking back to his door again and again, as if it might suddenly unlock for someone to enter unannounced. But everytime he looks, the door is still locked. And he himself is still alone in his room. Clad in nothing but a tshirt and his still dry pullup-- Slowly but surely, Keith finds himself sinking down into his little space. 

As he looks around his room, the most obvious thing that sticks out to him is the stark lack of babyish things to do. His dorm, like most of the Paladins, is pretty barren. There’s no TV to watch cartoons on, and not many furnishings to be played with or explored. But there is one object that catches the corner of his eye.

  
  
Keith swallows down his shyness and allows himself to crawl halfway under his bed and slide out a half-opened pack of pull-ups. Given he was already wearing one, he knew he didn’t really _need_ to put on another, but… how much thicker would it feel if he did? Would doubling, or even tripling up on them resemble real baby diapers? Would they crinkle when he walked, or restrict his movement enough to make him waddle? Keith remembers how Shiro held him in their laundry room the other night, and how he insisted to him that he didn’t need or want diapers, and snorts derisively at the memory. What a stupid lie. 

Standing up, Keith slips an extra pull up out of the packaging and slides it up his legs until it’s snug beneath his thighs. Reveling in the difference it makes-- The extra thickness, the slight resistance to his movement.-- And then adds a third just because he can. There’s no denying how fast he’s sinking now. How much he’s enjoying himself as he plops down onto his padded butt and shoves his pull-ups back under his bed. 

The next two hours are spent chest down on the floor, writing in his journal with his spare pen while he shovels spoonfuls of dry cereal into his mouth. But writing quickly devolves into practicing his ABC’s, and ABC’s quickly devolve into doodling. At some point he abandons his spoon in favor of his thumb, far too deep into his little space now to remember when or why. 

From spaceships, to hover bikes, to stars and cats and dogs, Keith gets lost in his drawings. Mindlessly filling page after page, until a distinct urge comes over him. The tight pressure in his gut, the anxious shifting of his hips. The ansty, almost nervous jumping of his thoughts- In the back of his mind, his adult-self is surprised he’s noticed at all. Keith sits up on his knees and sucks at his thumb, while the other one works back and forth over his index finger, suddenly overcome with conflict about how to handle it. 

He has a toilet for going potty, and he shouldn’t waste pull-ups. He’s not supposed to use them unless he has real accidents. And there’s no trash cans in his room-- What will he do with it after he’s gone? But then… He’s a baby now right? If he needs to go potty, shouldn’t he just go? He’s wet in his pull ups before, so it’s not like they couldn’t take the strain. And besides.. He kind of really wants to use them right now. Once the realization of desire hits him, all thoughts of risk and disposal are quickly forgotten. 

Situating himself comfortably on the floor, the little boy sucks on his thumb and does his best to relax. Concentrating on unfurling the tightly woven knot in his bladder, until he starts to feel a startling warmth rush out into his pullup. He’s surprised at just how easy it is to let go, completely unable to stop once he’s begun, but getting quickl carried away in the warm sensation to care. His breathing evens out and his cheeks flush a dusty pink hue as he soaks his pull-up. 

It feels so much nicer when it’s not all cold and soggy, Keith thinks, poking and prodding at the squishy material. Marveling at how bloated and swollen it is. It’s so nice, he can’t believe how good it feels to be so little. He’ll have to find a way to get himself some real diapers for the next time-- if his adult self allows him to, once he wakes up.

Bladder relieved, Keith stands on his knees to go retrieve a book when he notices that same sensation again-- Only it’s in a different spot this time. Just like before, there’s some hesitancy in the realization, but he’s already soiled himself once. What's the harm in soiling himself just a little more?

This time it takes a bit more effort, but it’s a lot easier to go now that he’s already gone a little. His tummy gurgles with impatience, and soon he can feel it all moving down as his body pushes it forward. Letting out the tiniest gasp around his thumb as he feels the thick warm mess emptying from his bowels and pressing against the seat of his pull-up. Just like before, once he’s started, he can’t stop. Cheeks flushing a bright rosy red as his sphincter goes numb and pushes it all out. Keith hears the smallest of gurgles and farts escape him in the process. The mess in his pull-up grows heavy and large. He had no idea how much he had to go until now, and the sting of embarrassment burns hot on his face, on the tips of his ears. Keith loves every single second of it. 

He’s hanging onto the edge of his bed when he opens his eyes. When he’s finished, Keith can’t help but reach a hand down to feel how plump and full the back of it is. Not quite straining, but clearly not designed for this purpose either. He’s gone so much; There’s no denying who he is now. 

His thumb is soaked with spit when he pulls it out of his mouth, only to push it back between his lips unthinkingly. His mind is so small and hazy right now. There's a thick, sweet fog clouding his mind from thought, taking him deeper into his little space than he’s ever been before. Basking in the warm, full mess he’s made. 

After Keith spends who knows how long mindlessly sucking his thumb and enjoying his messy, wet pull-up, eventually he remembers that he wanted a book. The baby distractedly crawls over to the tiny shelf at the edge of his bed. Inside there are several short, old volumes of classic novels and autobiographies by various authors. Some Keith knows, some he doesn’t. Usually he would pick one of the newer novels in Galactic Standard, so he could practice common alien reading. Or maybe one of the Altean romances Coran had lent him for study. But he’s so little right now, he doesn’t think he’d make much progress with it. So instead, Keith chooses one of the few children's books the space mall had available: Corduroy.

Being one of the few books he’d grown up with, it’d been impossible to resist buying when he saw it in the old aliens thrift store of the space mall. It had a few scratches in the paint, and some dog-eared pages, but it was otherwise in surprisingly good condition for an out of print book abducted from Earth. Keith quickly slid it out of his bookshelf and settled himself back on the floor to read it. 

He opened the stiff red cover and turned past the introduction and thankyou’s to the first page of the story. Above the first passage was a picture of a small brown bear standing on a shelf, wearing green corduroy overalls; One strap missing a button. 

  
  


_“Corduroy is a bear who once lived in the toy department of a big store. Day after day, he waited with all the other animals and dolls for somebody to come along and take him home.”_

  
  


Keith turned to the next page, and saw an image of a large mall filled with shoppers. The shelf on which corduroy sat was zoomed out to view how large and tall it really was, and how many other toys were displayed on it. 

  
  


_“The store was always filled with shoppers buying all sorts of things. But no one ever seemed to want a small bear in green overalls.”_

  
  


Keith flipped to the next page, and the next and the next. Allowing himself to be immersed in a long forgotten childhood tale of a bear searching for his button, and a home that would love him. He couldn’t help but empathize with the lost little toy. The intrinsic nature of his story, however simple, not dissimilar to Keith’s own. All the stories he liked tended to be that way though, for obvious reasons. Adult Keith could recognize this in a mature, and calm way- After all, it was just a natural consequence of noticing a pattern. Nothing more, nothing less. But little Keith was a different story. 

Every new page the baby turned sent Keith back to a new memory he wasn’t yet prepared to visit, or a feeling he hadn’t known he needed to let out. That deep, vacant hole in his chest was back again. Making itself known with every ache in his sternum and every beat of his heart. The longer it stayed open, the wider it became. Echoing and cavernous. 

Recognizing his emotions and walking away was already hard enough as an adult, but as a baby? It would take a miracle for him to pull himself together now.

Keith heard himself sniffling before he recognized the blur of his vision. Moving to sit up against the side of his bed so he could wipe away tears that had made trails down his soft cheeks, the baby book forgotten in his lap. This wasn’t how he pictured his regression going; Then again, maybe he should’ve expected this. He hadn’t let himself regress in a long time, and he hadn’t really been letting himself cry too much either. Both tended to make him feel like a baby-- why would he do anything else when he actually _was_ one? In hindsight, Keith felt stupid for ever thinking otherwise. 

Before he knew it, he could feel his breathing hitch and stumble in his chest. His lips wibbling at the thought-- Just as he was starting to calm down from the small, soft crying, he had gone and found another thought that Keith was sure would have him wailing and sobbing loudly in his room. In the back of his mind, he began to panic. What if someone heard? What if someone overrided the lock and came in and saw him? He had to calm down, he had to get big again. 

The little baby shut his eyes and concentrated as hard as he could on feeling big again, but everytime he tried he could feel the negative thoughts pulling him away again and again, unrelenting. Like holding on to monkey bars while someone kept prying off his fingers-- Each upsetting thought gaining more attention each time he tried to ignore them. The harder he tried, the more upset he became and soon Keith’s eyes were flooding with tears. His hands clenched into little fists raised to his cheeks-- It took every ounce of restraint left in him to stop them from flooding over and bawling, and soon he wouldn’t be able to stop himself from crying loud enough to draw the whole castle into his room. Keith just didn’t have the strength he needed to stop-- He was too little. He was stuck. 

A click. A beep. An LCD display turning from red to green prefigured the smooth slide of the lock on his door. It wasn’t until the panel of his door slid open with it’s distinct whirr that Keith realized what was happening-- and froze in place. 

“Rise and shine cadet. I know we’ve had a long day yesterday, so I.. “ Shiro said, stepping into Keith’s room only to stop at the sight before him. His sentence trailed off unevenly into a mutter, his expression going from shock, surprised, and then taking on a mix of awe and fascination, unable to hide his stare. “I.. Oh. Oh my gosh.”

There before him, sitting on the floor, was Keith. Clad in only his pull-up, a tshirt, and sporting some awfully red cheeks. The sight alone took Shiro’s breath away. An instant surge of protectiveness overcoming him so suddenly, his brain completely stopped in its tracks.

Keith could only stare back, shocked out of his tears and looking so incredibly adorable embarrassed at being caught like this. If nothing else, he was glad it was Shiro- Glad that he had someone now to stop him from himself-- But in that same moment, Keith felt his face turn bright red at the realization of Shiro walking in on him, seeing him like this after everything he had said the other night. 

Before Shiro allowed himself to do anything else, he closed the door behind him and locked it. Something Keith was immediately grateful for-- Until the large man turned around and covered his mouth for a moment. 

“Shi- Shirwo?!” Keith asked, voice unused and raspy from tears-- Eyes widening at the sound of his own tiny voice and it’s babyish inflection-- He’d never baby-talked before, but just hearing it between them, he wasn’t sure who was going to combust first. Keith from sheer mortification, or Shiro from raw, uncrystallized cuteness. 

Evidently it was Keith, because he couldn’t resist the urge to cover his face (and desperately attempt to hide his tears). “What- What are you doing? You should’a knocked fiwst!” He whined. 

Inside, Shiro was dying. He was dead, gone, and floating up to heaven. Goodbye world, it was nice while it lasted!

The black paladin was utterly at a loss for what to do with himself. Expression twisting painfully with so many emotions, it was overwhelming him. Frozen to the ground as his poor, unprepared brain worked to process everything in front of him. _“His voice. He’s talking like- like a --Oh my god, did he double up his pull-ups- His thumb is wet, was he-? Was he actually-- Oh fuck, omyfuckinggod he’s hiding his face, he’s hiding his face-”_ Never before in Shiro’s life, had he seen Keith so little. And the fact that Keith alone must’ve done this, without anyone elses help-- All his Guardian instincts were going crazy. 

“I- I’m sorry, baby. But- oh my gosh,” Shiro swallowed, pausing for a moment as he kneeled and hunched down to be eye level with his baby boy. “- What’s going on?” He asked, voice softening in an instant for the baby in front of him. “Were you playing by yourself sweetie?” 

From inside his self-imposed mask of arms and hands, Keith let out a long childish whine. Even with Shiro’s eyes all over him, he couldn’t help but calm down instinctively with the presence of his Daddy so close. 

Shiro smiled so hard his cheeks hurt. “Are you alright? How long have you been-- Baby boy, how did you get so _little_?” Shiro cooed, sidling up to him and smoothing his arms around his baby’s back, before hefting him up under his armpits so he could get a better look at him. Keith gave a short little yelp of indignation. “Daddy!! Nooo, don’t loook!”, he whined and began to squirm. All of which passed over Shiro like a vision from heaven itself. All the gravitational forces in the galaxy couldn’t hold back his smile, biting the inside of cheek at how cute it all was. 

“I’m sorry sweetheart, I just. I need to hold you. You’re so cute- This is so much.” He said, and gently brought Keith to his chest. Gingerly squishing him close, and trying to breathe past the rush of paternal instincts flooding him. “You’re so- You’re so unbelievable. Oh my goodness. How did you get so adorable?” He said, and kissed Keith’s forehead through his messy hair. 

Try as he might to resist Shiro’s care, hugs never failed to pacify him, and Keith found himself helplessly relaxing into his Daddy’s arms on contact. A soft, unintelligible mumble escaping him as his little space brought him back down. Maybe it wasn’t so bad if Shiro saw-- As long as it was just Shiro. Simply being held was enough to make all the bad thoughts go away, as the warmth of his Daddy’s chest and the soothing sound of his heartbeat overtook him-- The few tears in his eyes leaking silently into the hug. Keith decided to let Daddy have his way with him and do as he liked-- The hug was everything he had wanted, and it felt nice to be held while he was so little-- Not like he could really oppose him as he was right now anyway. 

Shiro took a moment to simply hold him. Using the contact to calm himself down as well, now that his little boy was safely tucked away into his arms. Only after a long couple of minutes had passed, did Shiro notice something. A sound he hadn’t ever heard on the ship before, appearing rhythmically every couple of beats, again and again. He raised his head to look for a source, only to realize it as coming from underneath him- From Keith. He looked down, and his little baby had his thumb in his mouth. Sucking away to his hearts content, eyes closed and utterly relaxed against him. 

_Hello? God? Yes, you can let me die now. I’m ready._

Another surge of shock and endearment surged through him at the sight. It hurt his heart to see his baby so little, so engrossed in his juvenile instincts. He had never sucked his thumb before, and it made Shiro all the more convinced that Keith needed him right now. He probably didn’t even realize he was doing it, judging by how embarrassed he usually got when Shiro caught him indulging even the slightest of immaturities.  
  


With a deep breath, Shiro leaned his head back and sighed. One big hand running over his baby’s hair and encouraging him to relax, as Shiro thought on what to do-- When another distraction took him by storm. There was a strange smell in the air, stinking and repugnant. At first, he thought Keith might’ve wet his bed again, and looked over towards his bunk, only to see the sheets rumpled, but otherwise perfectly clean. He sniffed about, sniffed Keith, and then finally pulled back an arm to inspect his little boy, and sure enough, his pull-up’s were swollen and sagging between his legs. 

“Baby boy,” Shiro began gently, as his human hand trailed down his back towards the waistband of his pull-up. Thumbing at it hesitantly, teasingly. “Did you wet while you slept again?” Shiro asked softly. 

At the question, Keith looked up to Shiro with wide innocent eyes. Pleading to him around the thumb still in his mouth, “Mm-mm! I was dry today Dada!” 

_“Dada” Oh god._ Shiro know how much more he could take. _Keep it together, keep it together_. “Are you sure?” He asked, making sure to keep his tone void of judgement. One hand situated on the small of Keiths back to keep him calm as he talked. His other hand coming around to the front of his pull-ups and absently counting the layers Keith was wearing. Three in total, but Shiro could estimate the bulk of the mess wasn’t coming from the third or the second. 

Keith nodded at him. “I swear! I was good!” Keep replied, his voice sounding a little desperate and-- upset? Shiro didn’t know how he missed it before, but Keith’s eyes were slightly red, shiny and watery. Just how much had he missed this morning?

One hand moved to cup Keiths face. “I believe you sweetheart. I do. But Keith--” Shiro paused, and moved his hand down to cup the bottom of his diaper between Keith’s legs, incidentally giving it a small squish and making Keith jump. “--You’re _soaked_. Look at this.” Shiro said. The surprise coming out as exasperation in his voice, and making Keith’s face burn from mortification.

Suddenly, Shiro was turning him to the side and bending him over to inspect him. One arm cradling him around his torso to keep him in place, while the other inspected the back of Keith’s pull-up. “I’ve never seen any of your pull-ups this full. Keith--, “ Shiro commented, his palm gently holding the large protruding bulk of his mess. “Did you poop?” He asked. The inflection in his voice a little too serious, a little too concerning to be one hundred-percent void of judgement. It made Keith feel like a five year old, caught sticking his hand in the cookie jar, about to receive a spanking.

“I- I. Um.” He stammered. Overcome with mortification, and far too embarrassed to answer. Anxiously sticking his thumb into his mouth to suck on it, and in doing so, telling Shiro everything he needed to know. 

The Guardians features softened once more, and without further ado, he pulled back the waistband of Keith’s heavy, soiled pull-up to confirm his suspicions. Only then did it really hit him just how little Keith was right now, and just how fast he was progressing into his juvenile tendencies. Shiro made a mental note to keep a closer eye on him for any signs of resolution. But for now, he had a little boy to take care of with a very, very dirty pull-up. 

“Aww, Baby boy, you went so much!” Shiro exclaimed, cooing at him teasingly. “No wonder, you stink.” He chuckled, letting the waistband go so he could feel how heavy the sag of his mess was in his palm. 

Keith squeaked, utterly mortified by the action and wiggled in Shiro’s grasp. “Dadaaaa! Stoooppiiiit!” He whined, prompting Shiro to chuckle even more, and pulling him back to give him a couple tender kisses on his face. 

“I’m sorry sweetie, I can’t help it. You’re too cute not to tease.” Shiro said, smooching his cheeks again and again. “But you are awfully messy right now baby boy. I can’t just let you waddle around in your pull-ups if you’re going to make messes that big.” To illustrate his point, Shiro rested a hand between Keith’s thighs and gently lifted the pull-ups swollen middle up and down. 

“You see how heavy and full this is honey? If you sat around in this for just a little longer, it would probably burst.”

“Weally?” Keith asked around his thumb, watching Shiro’s hand with rapt attention. 

“Mh-hm.” He nodded. “Pull-ups aren’t made to handle such big messes, sweetie. You need diapers for that.”

Of course, at the mention of diapers, Keiths head shot-up in defensiveness. “But, but you said if I was good and I didn’t wet the bed anymo’ then I wouldn’t have to wear diapew’s!” 

“And you _were_ good boy. You stayed dry all night last night, didn’t you?” Shiro assured.

“Mhmm!” Keith nodded.

“Then you don’t have to wear diapers at night, or in the day. Just when you’re a _little_ baby, and you want to go poopy. Because diapers are for big messes that you make when you’re a baby-- Not all the time. Do you understand baby boy?” Shiro said, taking both Keith’s hands in his own large ones. Grounding him and making sure he had his full attention, all at once.

At first, Shiro was sure Keith would understand-- But as he finished, the little ones eyes seemed to drift off and gloss over. Becoming more sad and reluctant to accept the truth. “Mmmn.. I guess so.. But…” The little boy mumbled, avoiding Shiro’s gaze. 

“But what, sweetheart?” Shiro prodded gently. 

Slowly, Keith met his eyes again. Now seemingly twice as big, expression forming a small worried frown, lips trembling as he spoke. “But I don’t wanna wear diapers! I’m not- I’m not a baby!” Keith blurted, taking one hand from Shiro’s grasp so he could wipe at his eyes, where tears were forming once more. His small voice becoming smaller as the little one tried his best to explain through sniffles and stray tears, finally allowed free. 

“Everyone’s gonna laugh at me, and call me names, and tell me mean things-- And I won’t be able to hewp people, or lead voltwon, and-- I don’t wanna be a baby! At least--” Sniff, “At least not forewer..” 

Shiro’s heart ached with so many things, watching Keith break in the most vulnerable state he had. For a long time Shiro had always understood this fear, and always wanted to help him come to terms with accepting that who he was and what he liked didn’t have to be the same thing. Now, as Shiro saw Keith frightfully exploring for the first time, scared of the consequences of his own enjoyment, he thinks, weirdly enough, it might just be the answer. 

“Keith,” Shiro spoke. His free hand reaching up to wipe tears from his boys soft red cheek, only to cradle it warmly in his palm. Eyes locked amidst stray tears and sniffles. “Wearing diapers doesn’t make you a baby. There’s no person, no force in the entire universe, and certainly no object that can make you anything you don’t want to be.” Shiro spoke, and leaned over to give Keith’s forehead a soft, quick kiss. Momentarily stopping his little boys tears.

“Only you can decide if you’re a baby. Wearing diapers has nothing to do with that.” 

“Really?” Keith asked, rubbing at the edges of his eyes. “ So… I can wear diapews and not be a baby?”

“Absolutely.” Shiro affirmed, beaming at him with a proud smile. “And I promise, if anyone ever makes you feel bad about it, regardless of what you decide, I’ll always be here to support you. No matter what.” 

Finally, like sun after the rainfall and moonlight peeking through the clouds, Keith smiled an honest to goodness smile. One hand still rubbing at a damp eye, while he mumbled the sweetest thing Shiro had ever heard. “I wuv' 'ou Dada.” 

Shiro, sure he was going to die of sweetness, was left with absolutely no choice but to tug Keith into another big hug and squish him tightly in his arms-- Making the baby let out a small giggle, before snuggling into the embrace. “I love you too, sweetheart. I love you so, so much.” he spoke, reveling in the way they relaxed in each other's arms.

Shiro waited until he could no longer hear any sniffles or hiccups coming from the little boy. Until his breathing had evened out and the soft sound of suckling had returned to his ears, before gently pulling back to look at him with a beaming smile. Keith was so incredibly, adorably cute like this. It was so rare for him to allow himself to regress, and even rarer for Keith to regress so young. 

There was just no way Shiro was going to let it all go to waste. Not if his role as Guardian had anything to say about it.

“Now then,” He said, giving Keith a swift kiss to the forehead and making him giggle. “How about we get you changed, baby boy?” 

\---

_To be continued, in Chapter 3: A Lamb in Lambs Clothing._

**Notes for the Chapter:**

> Hey all, thanks so much for reading! If you liked it, please leave a comment. It makes my day and encourages me to continue. <3 + i love hearing what you guys think
> 
> Here's a question for you guys; If I started my own discord server for fan art and fanfic, would you join? 
> 
> Last update: I made a separate account for other kinks I like writing for! If you like your humiliation in other flavors besides diaper, check out KickSomaesthesia!
> 
> Stalk me on twitter @kisskinesthesia


	3. A Lamb in Lambs Clothing.

**Summary for the Chapter:**

> The long awaited conclusion to the previous chapter, in which Shiro catches Keith regressing. Now, helpless to take care of himself, Shiro's decides to take matters into his own hands.

**Notes for the Chapter:**

> Warning: This chapter contains wetting, references and mentions of messing + cum, and sexual arousal in relation to regression. 

  
  
_The night before..._

Five hours of mission briefing, planning, gear prep, and pre-mission launch procedure. Two hours of silent waiting for the espionage team to successfully infiltrate and disable the Galra base on planet Meltan. _Sixty four Hours_ of heavy space-fire in and out of the lions to liberate the population. Seventeen hours of manual labor and providing resources, Six hours of meetings negotiating the new planetary alliance between peoples, and four hours of pre-flight preparation before finally leaving the planet. 

It’s been seven hours since they returned to the castleship with all their limbs intact. Six hours and twenty three minutes since he bathed, ate, laid down and closed his eyes. 

A total of one hundred and five hours of endless interstellar warfare, hostile enemy conflict, espionage, security, construction, manual labor, flight prep, negotiations and networking. And still, Shiro cannot sleep. 

His body aches with sores and bruises. He feels heavy in every tissue and tendon that holds him together. He’s tired. Bone deep with exhaustion. There is nothing in the world that he wants more than to fall into a nice, deep, dreamless sleep. But his brain- _His brain just won’t shut the fuck up._

Rarely is Shiro ever really here-- Here as in now. Conscious and listening. Real time, in the moment. In his body. Most of the time, Shiro is in his head.

Not in the present, but in the past, or the future. Dueling with demons that never quite leave him, always on the edge of paranoia, worried and anxious over the next correct step to take. The next enemy they’ll face. The next planet they’ll save. The when, the where, the how to take care of everyone and everything. Because he can never have enough back up plans, never live up to his own ideals of perfection, and something will always find a way to go wrong.

Preparing for the unknown was one of the few things that gave him momentary relief-- Both poison and antidote to a bottomless anxiety that would never quite leave. 

So Shiro thinks and thinks and thinks. Forever remembering yesterday so he might save tomorrow. 

Possibilities whirr through his head faster than he can go through them. He thinks about all the flight prep they did, and all the flight prep they didn’t. The food dispensary will need to be cleaned and replaced soon, as well as ingredients. They need to work on their battle formations, on and off the ground. Lance seems to have gotten up in arms with Keith again, right after he’d thought they’d ironed things out. As a leader, his confidence has increased, but Keith still hasn’t been with the team in a while. Now that the dust has begun to settle, it’s becoming more and more obvious. They could use a good bonding exercise to get them all on the same page. 

_Keith..._

Just the name has Shiro switching gears. He turns his head to the side and tries to envision the smaller paladin sleeping in the next room, safe and sound. 

They were both so exhausted when they got back. Shiro realizes he forgot to make sure Keith wore protection before bed, and feels a wave of self-hatred wash over him over the small, personal failure. A private frown tugging at the corner of his mouth. He should’ve made sure of that. He made a promise, after all. But Keith was a light sleeper. No doubt Shiro would wake him if he knocked on his door to check on him now. 

It was obviously making him anxious having to wear pull-ups like that-- Knowing Keith, he’d let it get to him, and then the rest of the team would pick up on it-- And when they did, Keith would hole himself up and push everyone away just like he always did. An obvious worst case scenario Shiro would like to avoid- But that was Easier said than done. 

He used to baby Keith all the time in their garrison days. In the privacy of their dorm rooms, between training and study sessions. He would always play with his fingers, reach out for hugs and kisses, clinging to his side and falling asleep wherever he was sat, whether it be on the floor or in his lap. In exchange, Shiro got to play with him, care for him, and pick him up and hold him whenever he liked. In doing so, they gave each other a mutual outlet; Keith for his regression, and Shiro for his Guardian Instincts. 

To his knowledge, Keith never felt comfortable regressing in public like most babies. He’d always told Shiro he’d done it alone, and that he had been the singular exception- Something that had always worried him. As a Juvenile, regression was so vital to staying healthy, many babies commonly fell ill, or suffered permanent injury by repressing it. 

  
  


Had Keith regressed even once since becoming a paladin? Shiro doubted Keith had let himself regress once since entering orbit-- or maybe even since he’d left for Kerberos. 

It may have worked as a teen, but Shiro knew that as he got older, Keith would start settling into his cardinal role. Shiro himself had already sunken into most of his Guardianship by the time he turned 24. At best, the wetting accidents were just the first sign of it. At worst, it could be significant of a juvenile struggling with something serious. 

If he could just get Keith to indulge his little-space more often, maybe the bed-wetting would subside.

That, and-- though Shiro felt guilty for it-- he missed their time together. He craved so badly to care for his former pupil again. He wanted to go above and beyond the small paternal practices Keith had allowed and do for him what most Guardians did for their littles. He wanted to build his baby’s nursery, make him meals, feed him, change him, and so much more. 

But Shiro respected Keith’s wishes too much to ever go against them. He refused to force it on Keith when he knew how frightened he was of it-- Not unless it was absolutely necessary. 

But.. maybe that didn’t mean he couldn’t indulge himself, while respecting Keith’s wishes. He may have not had a nursery, but he did have a room to store things in. And.. well. It would be nice to have just in case Keith ever _did_ want to indulge himself, wouldn’t it? In case of a regression emergency? 

He knew Keith wouldn't want them-- and his heart panged with guilt at the thought-- but making preparations for situations always made Shiro feel a little bit more at ease, even if the situation itself would never come. 

At the time, it had seemed as good an excuse as any to do something he liked to get his mind off of things-- So that night, Shiro had allowed himself to wander around the castle and alchemize some baby items for Keith, and hole them up in his room. It had started out as simple as one or basic supplies-- and quickly grew into a whole storage container. After he was done fawning over each little item he’d made, Shiro was overcome with shame. They were no doubt wasted resources at worst, and evidence of his sins at best. Sad and pathetic-- Never be used for anything except to indulge a fantasy that would never come true

Or so he’d thought. 

Now Shiro couldn’t have been more glad he’d done that. 

  
  


“Now then,” He said, giving Keith a swift kiss to the forehead, and making him giggle. “How about we get you changed, baby boy?” 

It might have just been residue from the tears, but Shiro could’ve sworn Keith’s reddened cheeks grew just the slightest bit brighter at the suggestion. Giving only a nod to show Shiro his consent to the offer, and little else. No doubt realizing what was to come now that Shiro had caught him in this state.

“Good boy.” Shiro said, unable to resist pecking him one more time on the forehead, before hefting him up into his arms with one big swoop. Making his baby giggleand carrying him bridal style towards his door. “I’m gonna take you to my room to change you, okay baby boy? I promise, I won’t let anyone see you.”

Of course, Shiro saw the immediate way Keith tensed up. A low whine ebbing from his throat, free hand gripping Shiro’s jacket while the other sprang back up to suck at his thumb nervously. It was unclear whether his usually fussy baby would fight him on this, but still Shiro rushed to assure him anyways. 

“Don’t worry. Daddy’s going to peak outside first and check. That way, if there’s anyone outside, Daddy can come back in before anyone sees you.”

At this, the grip on Shiro’s shirt eased, but the worried noises emanating from the baby did not. Keith would never be completely comfortable with the idea, so Shiro supposed he might as well just get it over with as quickly as possible. 

Unlocking the door, Shiro turned around and walked backwards out into the hall-- Backing out only enough for him alone to be seen, looking up and down the hallway to confirm no one else was around- Then making the short bee-line to his door a mere three meters away. 

As soon as they were inside, the door shut behind them. Shiro quickly hitting the lock switch with his elbow before turning his attention back to Keith, who’s grip had tightened on him harder than ever. Head tucked stubbornly into his shoulder, trying his best to hide from the world even now. 

“Baby boy,” He cooed softly, rocking him back and forth. “You’re safe now. No one can see you but me.” 

With all the patience of a natural geographic photographer, Shiro watched and waited until the baby in his arms slowly unfurled like a flower from his chest, hesitantly peeking wide wary eyes out at the world only to be greeted by Shiro’s smiling face. “There you are.” He beamed, “My cute little boy~” Shiro chuckled, and brought him up closer so he could rain kisses all over Keith’s face, resulting in a whole lot of squirming and muffled giggling. 

Of course, the little baby in his arms whined even amongst his giggles, still flustered by all of this. In Shiro’s defense, he hadn’t taken care of his baby in years, there was a stash of baby items in his room just waiting to be used, and he was holding a very adorable teary-eyed baby who still was in desperate need of a diaper change. His Guardian instincts were kind of overwhelming right now. 

“You’re all mine now baby boy.” He crooned sweetly, something the baby in his arms. After a small kiss to his forehead, Shiro gently laid him onto his bed. 

“Let’s see now,” The Guardian hummed, and leaned down to pull out a dark plastic tub from underneath his bunker. Held inside were all the baby items Shiro had alchemized for Keith last night, stacked and folded in an organized manner for easy access. Just looking at it and knowing he was finally going to use them was nearly enough to make Shiro’s face split. But first things first. 

Rummaging through the bin, Shiro pulled out several items: A changing pad, wet wipes, baby powder, scented trash bags, and some extra thick baby print diapers with multicolored alphabet blocks on them. He laid them all down next to Keith on the bed, spreading out the changing pad before gently moving Keith onto it-- A little curious noise ebbing from the baby as he did. 

When Keith woke up from regression Shiro knew he would have a lot of explaining to do, but as a Baby, Keith didn’t seem to think much of it other than a new object he had yet to see before-- Which Shiro found adorable. 

Leaning over, Shiro lifted Keith's arms up and tugged his nightshirt up over his head, leaving him in nothing but his soiled pull-up and his thumb in his mouth. _Absolutely precious._

Giving him a quick tickle and smooch on the cheek, Shiro lifted Keith ankles and finally went about the task of changing his babys diaper. Tearing at the tabs on either side of his hips, Shiro pulled down the soiled garment to reveal the large mess Keith had made in it. Lifting Keith’s hips up by the ankles with one hand and grabbing a few wet wipes with the other, Shiro removed the dirty diaper from under him and wiped him down. Making sure every inch of him was clean before laying him back down on the changing pad and depositing the soiled material into a plastic bag. 

“Daddyyy,” Shiro heard Keith whine from beneath him. “I cold.” 

“I’m sorry, baby. Daddy will get you all warmed up in just a moment okay?”

“Mmmn, Okie.” 

Cleaning his hands with an extra wipe, Shiro grabbed a new diaper out of the pack and began unfolding it in his hands-- Watching for Keiths reaction as he did so. The little boy didn’t seem to notice it, instead watching the ceiling and wriggling about absent mindedly. 

Admittedly, it was a little bit hard to tear his eyes away from this: The sight of his blushing baby boy during a diaper change. Something Shiro knew he’d remember fondly already. 

Not intending to make him wait any longer, Shiro lifted Keith's hips once more and slid the fresh diaper underneath him. Laying him back down and adjusting it as needed, before sprinkling some baby powder onto him and pulling the thick bulky baby diaper up between his thighs and taping it snugly to his hips. Keith watched, more transfixed than upset by the sight of the diaper fastened to him, and wiggling cutely in the crinkly material. Hefting him up by the armpits, Shiro sat him upright to check his work. 

“How's that feel, baby?” He asked, watching him once more for any sign of displeasure. 

Keith looked down and wiggled in the new garment experimentally. Thumb half inside his mouth as he did so. 

“Mmmm.. It feels soft.” 

Shiro smiled so hard, he thought his face would split in half. _Keith liked them._

“Not too tight?” he asked, pulling back at the waist band a bit. 

“Hmmmm…. Mm-mm.” Keith shook his head.

“Good.” Shiro kissed his cheek and pulled Keith’s thumb from his mouth teasingly. “Cutie.” Making his baby whine predictably, before putting his thumb right back into his mouth without a second thought. The sight was so utterly infantile Shiro couldn’t help but stop and stare for a bit, just drinking in the sight. 

Now all that was left to do was clothe him.

Clothing-- Shiro looked over to Keith’s discarded shirt laid on the bed. He could put him back in it, but the shirt was a bit messy looking when he’d taken it off. Keith needed something clean. 

Shiro supposed he could always go back to his room to fetch him some cleaner clothes, but then he’d have to leave Keith alone in his smaller state-- Which unacceptable. No good Guardian would leave their baby unattended. And Shiro knew taking him back to his room would risk another sighting, and potentially upset his baby more. 

By process of deduction, the only clean fitting clothes Shiro had for his baby were the baby clothes he’d made for him the other night. 

Just the thought made Shiro inhale deeply. It was a tempting thought, but there was no way Keith would approve of being dressed that way. But as he looked over to the boy in question, seeing his little one beginning to squirm and shiver from cold-- Shiro’s decided it couldn’t be ignored. 

Diving into the tub of supplies, Shiro pulled out two folded legless onesies. One was printed with dinosaurs, all colored in a variety of greens and turquoise blues, and the another was printed with red cars, green trucks and blue planes strung about between white clouds. Shiro held them both up for Keith to see. 

“Which one do you like more? Dinosaurs, or cars and planes?” He figured that if Keith had to be dressed like a baby, he might as well get some choice in it. 

Keith, swinging his feet over the edge of the bed and humming around the thumb in his mouth, took a moment to think before pointing to Shiro’s right. “Pwanes!”

“Cars and planes?” Shiro asked to confirm.

“Yes!”

“Then cars and planes it is.” Putting the dinosaur print away, Shiro unfolded the garment in his hands and held it up for Keith to see. “Hold out your arms for me baby boy.” 

Keith did so obediently with one arm-- forgetting the other so he could keep sucking his thumb, and utterly _murdering_ Shiro from cuteness. Forcing Shiro to gently pry it from his mouth so he could pull his arms through the long sleeves of the onsie, before tugging it loosely over his chest. 

Once it had covered him, Shiro playfully pushed the baby down onto his back-- Making him bounce and giggle while Shiro drew the last of the fabric over his diaper and snapped it at the bottom. 

“There we go. All done.” Shiro admonished, patting his padded bottom before he could help himself. Tugging here and there at the garment until he was satisfied that it fit well. “Hows that feel baby? Not too tight?”

“Mmm..no. Warmmm.” Keith murmured, slurring his words a little. 

The smile Shiro wore reached all the way up to his eyes. “Wonderful.” He spoke, giving his baby another soft kiss on the forehead before pulling back to stand at the foot of his bed. 

Shiro hummed as he watched him, thumb working over his impressive jawline. Sure, the onsie was cute, but was there anymore he could do for him like this?

Experimentally, he plucked some soft white knee-high socks from the tub and slid them up over Keith’s legs. This would help keep his little feet and calves warm, but something still felt off. It was only when the distinct sound of Keith’s suckling interrupted Shiro’s thoughts that he remembered. 

Shiro bent down to rummage through the bin once more, and pulled out a small blue pacifier. After taking it to his bathroom for a quick rinse in the sink, Shiro plopped it into Keith’s mouth and waited excitedly to see if he would take to it-- Only to see Keith all but mindlessly suckle the rubber nipple once inserted. 

Shiro has to cover his mouth momentarily to withhold his scream. It hits him then for a second time that day just how tiny Keith is right now, and before he can think better of it, his guardian paternal instincts are overwhelming him again, and he reaches down into his storage bin for yet more supplies. 

By the time Shiro’s done, Keith’s adorned with a large baby bib and pacifier clip. The bib itself is white terry cloth, but baby blue satin lines it’s edges. In the middle, embroidered with a rounded font is simply the word “Prince.” adorned with a tiny crown.

Stepping back to look him over, no one could deny- Keith looked pretty damn cute. -So much so that Shiro couldn’t help but lean over him and drop kiss after kiss all over him. On his nose, his cheeks, his brows and forehead. At first Keith seemed confused, but almost immediately burst into a smile, and began to coo and giggle at the attention.

_Just like a baby,_ Shiro thinks, unable to stop the thought before it enters his head and fills up his heart, until it feels full to bursting. 

Shiro hovers for a moment, affection covering his face, before simply hugging Keith to his chest. His little boy had been slightly confused, and slightly bored before-- Now he squeaks in surprise and looks around with big eyes, questioning why Shiro suddenly hugged him-- Still not yet used to being hugged for no reason. 

Shiro offers no such thing. Only pulling back the smallest bit to deliver another peck onto his forehead, unable to resist looking at Keith with so much affection and endearment as he smooths locks of hair from his face, each tender touch lingering into a pet on his sweet little head. 

He’s already thinking about giving him a bath later tonight. Making him food, feeding him in his lap-- Maybe even a highchair? Could he make a highchair? There’s something of a dreamy sigh escaping his lips, before Keith’s tiny little yawn breaks him out of his reverie. 

Shiro snaps back to reality to find his little boy’s eyes half-open between blurry blinks, the suckling of his pacifier becoming softer and slower with each passing minute, causing Shiro’s heart to melt where he stands, as well as whatever expression he’d been wearing before. 

_Smooch._ “I think someone could use a little nap.” He comments idly, offering it up for argument-- But Keith only responds with more slow blinks, and more soft suckling. Too little to even protest anymore. It takes Shiro a moment for him to realize it, hitting him with a squeeze to his heart, before he's overcome with a need to hold him once more, and wraps his arms tight around his baby.

There's a soft, relaxed little coo from the form beneath him, before Shiro picks up his little one with one large hand around his back and brings him to his chest to doze softly while Shiro get's the bed ready. One handedly, he puts away what he can and clears the changing supplies off the sheets. Peeling back the thick navy duvet by the thin, white cotton sheet underneath it, before sliding into it. He situates himself at the edge of his queen-sized bunk, so Keith's small form lays between him and the wall-- Preventing the baby from tumbling over the edge and onto the floor. 

With no squirming or fidgeting, Shiro pulls back just enough to see Keith's face, only to find his eyes barely open. Little fists tucked to his chest. Soft, even breaths leaving him. Shiro's own relaxed sigh grazes Keith’s hair at the sight of him, before Shiro's bringing his little boy in close again- But this time, without the urgency or anxiousness. Right now, everything he needs is right here in his arms.

Keith wiggles a little to get comfortable. One hand unfurling to grab some of Shiro's shirt at his side, while Shiro reaches across them with an arm and moves to cover them with blankets, before they return to hold Keith in their rightful position.

"Goodnight baby boy." Shiro whispers, and gives him a tender kiss on the forehead. "Sweet dreams."

Keith, much too exhausted from play and tears to respond, says nothing back. But under his mussed bangs, beyond the small fist curled to his mouth and the pacifier between his lips, Shiro sees a content little smile.

Like a weight removed from a balloon, Shiro finally drifts away into a deep, deep recuperating sleep; Now with Keith in his arms.

* * *

Two hours pass, and like an anchor tying him to safety, Keith wakes to Shiro's heavy arms holding him in his bed. 

For a while, there is no thought. Only the sensory of it all. The warm feeling of being enveloped in layers of sweet, Shiro-scented cotton and linen. The safe weight of Shiro's big, strong arms around him, holding him tight-- Keith thinks of trying to wriggle free, just to see if he could, but he doesn't want to wake the sleeping Guardian before him, who's normally stern, stressed features have finally eased into relaxation-- A rare sight, even for a sleeping Shiro.

It's when a small smile climbs up his lips at the sight, that Keith finally notices anything off-- That something being what's _between_ said lips. The somehow old yet new feeling of plastic in his mouth would've shocked him if he wasn't just so comfortable there. Keith looks down, movement slow as to not disturb Shiro, and gently brings a hand to his mouth to remove the foreign object, only to pull out a pacifier-- Still soaked in his own spit, a trail of saliva still connecting it to his mouth.

In an instant, Keith remembers' everything. Their mission, their flight home, the morning after-- Holy shit, the morning after. He- He-- What he did-- Keith can't even think the words- And Shiro found him. Found him _like that._ \- Oh no. Keith tries his best to remember everything else, but the memories are foggy and mixed. Either not that much happened after, or Keith was too little to remember it-- Or both. 

He remembers Shiro commenting on his pull ups-- A memory which sends blood equal parts up and down through him-- and suddenly looks down at himself, needing to know if he's still wearing it or not, only to find worse; A baby print onesie with cars and trains and little toy planes flying across the pattern. His hand reaches down to check himself, much too dark to see under the covers, only to find a thicker, crinkly padding between his legs that Keith can only assume is some kind of diaper. When he checks the back, he knows it has to be. The mess he made before is all gone.

"Having fun?" Shiro asks, making Keith practically jump out of his skin as his eyes snap up in surprise.

Face flooding with shame, Keith jolts to full awareness in a microcycle. "Shi-Shiwo! You- Wait. I meant Shiro! Shi-RO! Shi- Fuck." His hands clap over his face, and it's over. His life is over. He was a little baby and Shiro saw it all, and now Shiro is smiling at him and babying him and it's over. Wishing the earth could swallow him whole and far too overwhelmed to deal with this anymore, Keith flops onto his other side so he's facing the wall, grabs his pillow and hugs it tight to his chest, face smothered and hidden away in the safety of its fibers.

From behind him, Shiro laughs. Soft and amused, yet terribly endeared. "Awwww, sweetheart." He coos, before his arms return to envelope him again, bringing Keith close to spoon him against his chest. "It's okay. Everything is okay. There's no need to be embarrassed or ashamed. You didn't do anything wrong." He soothes, voice gentle in Keith's red hot ears. As much as he hates to admit it, it helps. And after about ten or twenty minutes of comfortable silence, Keith finally emerges from his pillowy safe haven to greet Shiro-- Who beams at him in that utterly lovesick mix of affection and endearment that has Keith going right back to hiding his face all over again. "Awwwhaha!" Shiro laughs, giving him another hug.

Finally, Keith puts down his makeshift shield and sits up a little. Not quite able to meet Shiro's eyes, but no longer hiding. He can't stop looking at the print he's wearing, and-- Now that he has a better look at it-- The obvious padding at his crotch.

"Why am I dressed like a baby?" He asks. Obviously still embarrassed, but unable to keep the question out of his mouth. Part of him worries Shiro will answer him poorly-- the classic insulting, "Because you are one" replaying in his head fearfully to spite him. -- And Keith has to forcefully remind himself that this is Shiro, and he wouldn't. But Keith knows for a fact that these clothes don't belong to him either.

Shiro sits partly up at the question, and has the grace to look a little bashful himself. "Well, if that isn't the question." He hedges, one big hand moving to scratch behind his head nervously.

Guess they both had some explaining to do.

Keith doesn't answer. He waits. The forward stare of his eyes cutting the atmosphere, despite the heady blush still left on his cheeks. Finally, Shiro breathes out, "I'm sorry." And Keith waits some more.

"After I found you in your room, I took you to mine so I could clean you. But after I did, I didn't have any clean clothes left to put you in."

Keith's brows furrow in suspicion, lips jutting out defensively at the information. "So you made these for me instead?"

"No." Shiro says, a little fast. "Well, yes. But not today- Let me explain." He says, holding his hands out placatingly. Keith crosses his arms, and wills himself to be patient.

"I made those baby clothes for you last night, before our mission. I knew you wouldn't want to wear them, and I had no intention of making you. I made them for myself because..." Shiro looks away, pink climbing his cheeks. "Because it was nice to fantasize about.. babying you in them one day."

At the admission, Keith's expression softens. Sometimes he forgets, amidst all the teasing, how sincere Shiro is in his affection. That not all of his Guardian instincts exist to torment him. 

"I wouldn't have even showed you it, had there been anything else for you to wear." He continues. 

"Why didn't you just grab some of my clothes?" Keith asks.

"This might sound overprotective, but I didn't want to leave you alone by yourself to do that. And you were already pretty shaken when I had to take you to my room in the first place. I didn't want to upset you more by making you go out again while you were still so… So..." Shiro trails off. He doesn't need to fill in the gap. Keith knows. "If there were any other fitting clothes to give you, I would've put you in those instead. I swear." Shiro adds, deep greys boring into him with painful sincerity, and Keith knows he's telling the truth. Even adult Juveniles can choke or hurt themselves in clothes that are too big for them, and Keith knows Shiro is mindful of that too. Shiro would probably feel more comfortable putting him in his own, bigger clothes, if there were more instances to prove that a regressed Keith would be okay in them. Instances that Keith could have provided already, if he would be more open to it.

Keith uncrosses his arms with a sigh, eyes leaving Shiro to stare at his own lap. His adorably baby-printed lap, trying his best to believe him. It's not until Shiro crawls forward, face full of genuine guilt, and says "I'm sorry.", that Keith can make eye contact again.

"I knew you wouldn't like it, and I'm sorry. I just wanted to take care of you." Shiro says, with all the emotion of a big puppy dog, begging for forgiveness after doing nothing wrong. The look on his face is too much to bear, and it's too much to stay mad at for long.

"... I did like it." Keith admits quietly, with a little gulp. Shiro's face alights momentarily with a look of surprise hesitance-- As if he's not yet sure whether he's allowed to be happy about this or not. "And I'm sorry too."

Evidently Shiro _is_ allowed to, because his face relaxes into a soft smile once more, and he smooths his way into another hug. Arms gingerly stretching around Keith's back, and Keith allows himself to lean into it, face pensive as he processes the small hurt. "There's nothing to be sorry for, baby boy." Shiro says with so much sincerity, it could choke him. All the hurt and defensive suspicion drops from Keith's face in an instant. Eyebrows worrying up at the older man instead.

"There isn't?" He asks. "But.. I didn't tell you that I.. I wanted to.." Keith crews his lips. He feels bad. The one time he decides to indulge himself, he leaves Shiro completely out of the loop against his wishes. Not even thinking about how worried or stressed Shiro might be, knowing his baby was regressed and unsupervised.

But Shiro doesn't seem to be bothered. "Mm-mm." He hums, shaking his head. "There's nothing wrong with you being little by yourself, sweetheart." He says, and by accident or by instinct, scoops Keith up and settles him into his lap, cross legged. If it wasn't so comforting, Keith might be more scandalized about it.

Instead he leans into the soft embrace, face still an unsure mix of emotions. "But...." Keith pauses, finding his words. "You're always going on about how I should let go more. And you just said that you made these clothes for yourself-- Didn't I hurt you?"

"No, baby boy." Shiro answers soothingly, and drops another kiss onto his head. "I'm happy that you let go, and you enjoyed yourself. It's okay to want privacy for that. You weren't lying to me, or trying to hurt me."

Keith's lips warble into a grateful little smile. Shiro knows him so well. "I wasn't."

"I know." _Smooch,_ "I know you weren't, sweetheart."

Finally, Keith's arms move to hold Shiro as well, and Shiro leans down to fully embrace him in a small, loving hug. It's a sweet, soft squeeze that has Keith smiling in his arms, momentarily forgetting himself. _Until_

“So. When were you gonna tell me how much you liked pooping your diapers?” Shiro asks, ruining the mood and lighting Keith’s face on fire.

"What!" Keith squeaks out, jolting in Shiro's arms. "I- I don't!" He defends up at Shiro, who only smiles down at him with a smug expression that tells him Shiro knows he's lying, and it strips Keith bare in his lap.

"I -I don't!" He tries again to sound more convincing, and somehow manages to sound less. Cheeks hot enough to burn milk at this point. "Shiro that's so- That's gross! Why would I- I wouldn't-!"

"Keith." Shiro cuts him off. "I changed your diapers. I saw what you left in it.” He says, and Keiths eyes go wide as lightning strikes him where he sits. Time stops, and for a brief moment, so does Keith’s heart. Shiro-- Shiro _saw_. 

“You didn't just let go, baby boy. You _came_." Shiro admonished, calm yet cocky as he confidently laid out all Keith's sins. One big hand coming to cup his soft cheek so Keith couldn't escape his eyes. "Now tell me, baby. Just how much do you love going poopy in your diapers? Hmm?"

"I-" Keith blanks. He should be dead right now, but something in his hindbrain clicks instead at the way Shiro talks to him, and Keith finds his mouth moving despite him. "A wot."

The flash of surprise on Shiro's face is so fast, Keith almost misses it. He doesn't blame him-- Keith's surprised at himself too. Wasn't he done being small for today?

"A lot, sweetheart?" Shiro asks, needling for more, and Keith throws up his hands to hide his face unthinkingly. He can't believe he just said that.

Cooing at the adorable display of embarrassment, Shiro rubs Keith's back up and down. Encouraging his baby to hide in his chest for as long as he needs. "My cute little boy. Daddy knows you're baby. Daddy knows you like being a baby. And Daddy _knows_ that _you know_ , you like being a baby." He says, dropping another kiss into Keith's hair. "Don't you?"

From beneath his hand, Keith's back moves up then down in a big sigh. He’s reluctant, but there’s no use in hiding it in anymore. There’s no use trying to fool Shiro anymore, and he’s certainly never fooled himself. "I do." He says, turning his head to the side so Shiro can hear him, and Keith gets another soft squeeze for his efforts.

"Then lean on me, Keith. I'm your Guardian. _Your_ Daddy. There's nothing I want more than to give my baby boy everything he needs." _Smooch._ "So what does my baby boy want, hm?" Shiro asks, "Tell Daddy what you want, and Daddy will take care of everything. If you want to make large messes in your diapers, Daddy can help with that. If you want your diapers to be so thick you can't walk, Daddy can help with that too." He says, giving Keith another kiss while his face burns with every word.

After a moment of drowning in his own blush, Keith says, "Really?" Voice hopeful yet meek. Juvenile sexuality wasn't uncommon, but it wasn't often met well on Earth either. Often it was seen as disgusting, or impure. Making the Juvenile too soiled for any good home.

"Really." Shiro affirms with another kiss, hand sliding up and down his back.

"It's not..." Keith's eyes drift around the room, "It's not.. weird?"

"No, baby boy. It’s not weird at all." _Smooch_ , "And if you want Daddy to embarrass you or tease you, or tell you how cute you are, well-" Shiro grins, launching into a barrage of kisses against Keith's face that ends in a large raspberry against his cheek-- Making Keith squeal and laugh in such an utterly adorable little voice, Shiro can't resist giving him one or two more on the house. Giggles still ebbing from the little paladin, Shiro unabashedly snuggles him. There's no escaping now. "Daddy's happy to do that too." He grins. 

"Now tell me. What does my little boy want? We have all day to play, you know." One of Shiro's big hands gingerly slips underneath his bottom and gives it a few soft pats, noting the way it seems to soothe the baby in his arms.

"I wanna..." Keith starts, a little hesitant. "I wan' food." He says, tongue slipping a little. "And I wan...I wanna pway."

"Oh?" Shiro says with interest. "Daddy could make us a little late lunch. And then I could show you some of the toys I made for you." Shiro smiled, kissing his forehead. "How about that?"

Against himself, Keith beamed brightly right back up at him. A shy little "I would like that." Escaping him in a near whisper, full of mirth.

God, Shiro loved him, and couldn't resist pecking his forehead with kiss after kiss, making Keith squirm and giggle some more. "Good." _Smooch smooch smooch_. "But I have one more question before we get started sweetheart."

"Yah?" Keith asked, carried away on kisses and slipping in and out of baby talk.

"Are you still little right now, or big?" Shiro asked. In truth, this had been worrying him since he found Keith so this morning.

Keith takes a small moment to answer, and the more he takes, the more unsure he seems to look. Finally, he looks up at Shiro with both his hands balled at his sides and says, "I.. I dun' know." Shiro gives him another hug and a couple head pets to comfort him, trying his best to assure Keith as much as he can.

If Keith really couldn’t tell, it meant bad news for the head of Voltron. 

"And this morning, sweetheart; Can you remember how you got that way?" Shiro asked. This time, his answer is much quicker, as Keith nods his head yes. "I wanted to... try letting go." He mumbles.

"But you couldn't get out of it when you tried." Shiro says more than asks. But when Keith nods his affirmations instead of correcting him, his suspicions are confirmed. Keith _is_ starting to involuntarily regress. Even now, Shiro's sure what he's seeing is Keith slipping in and out of Juvenile tendencies. Although now that he's regressed a little, Keith seems more cognizant. A little more aware.

"I don't mean to scare you sweetheart, but I think you're starting to regress more often." Shiro says, brushing back some of Keith's dark locks over his ear. As expected, Keith's face saddens-- But he doesn't cry. Instead, he sighs. Bringing up his hand to cup Shiro's as it settles on his cheek once more. "I think so too."

Is it good? No. But even Keith doesn’t like the idea of running away from this until it eventually consumes him. Especially not at the expense of Voltron.

Shiro gives him a proud smile for the admission. "How about we set up a play-schedule for you then?" He suggests. "The more time you allow yourself to regress, the more you should be able to control it. That way you won't be going in and out of regression in the middle of missions." _Smooch_ "Sound good?"

Keith nods for him, but his smile is distant. His mind somewhere else. "What awe we gonna tell Allura and Coran?" Keith asks, slipping again.

"You just leave that to me. Old injuries, allergies. Human conditions that advanced, civilized Alteans such as themselves couldn't _possibly_ imagine." Shiro intones sarcastically with a roll of his eyes, making Keith laugh despite himself. Shiro was rarely able to express his more pessimistic and judgmental opinions, but like everything else, Keith was the only exception. 

"We'll figure something out. Right now, I'd like to help my little boy enjoy himself." Shiro says, pushing back Keith's bangs to land a nice long kiss on his forehead that has Keith smiling all over again. "Mmmmmmmmmwuah!!" He hums, smacking his lips as they leave his forehead just to make Keith giggle, only to make himself laugh too.

Despite the long time fear of losing himself to his Juvenile tendencies, Keith found that he wasn't scared anymore. Shiro was here, showing him that as long as he met his own desires halfway, he would always be in control. 

But then there's a hissing sound, and that familiar feeling of warmth spreading at the bottom of his diaper. Shiro goes "Oh?" Like someone's just handed him an interesting study documenting all the ways Keith Kogane can die of embarrassment, and looks pointedly down at where Keith's sitting. Warmth from his diaper no doubt spreading to Shiro's thigh through his sweats. Shiro's grin is so big and bright, it could have its orbit. "Awww, sweetheart. Did someone have to go?" Shiro asks, and Keith feels his regression wash over him like a warm wool blanket on a hot day, slipping his thumb into his mouth on instinct to soothe his burning cheeks.

Well. _Mostly_ in control.

And so, as Shiro rubs his back and rocks him back and forth until he's finished, and then lays him down for his next diaper change, Keith slips back into blissful babyhood and thinks that maybe this won't be so bad, if he has Shiro by his side.

The two spend the rest of their day relaxing in Shiro's room as Guardian and Juvenile, Daddy and Baby. Finally giving into the roles they were born to take, and desperately trying to make up for lost time.

**Notes for the Chapter:**

> Merry Christmas Babies! 
> 
> Sorry this chapter took so long to get out. This is by far the the most popular fic I've written, and even now I still get new kudo's and comments for it. They never fail to brighten my day or bring a smile to my face, even throughout this terrible year. For everyone who left a kudo or a comment, thank you so much. 
> 
> I hope you enjoy this extra special Christmas gift. <3 
> 
> bug me on twitter @kisskinesthesia, for i am lonely and want friends!!!  
> also join pillowfort because it's rad! And have a happy holidays <3
> 
> Edit: WE HIT 5000 HITS!!! THANK YOU SO MUCH!! <3


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